8.  The applicants were born in 1950, 1966, 1972, 1981, 1982, 1984, 1986, 1990 and 1993, respectively, and live in Diyarbakır. The first applicant is the wife and the remainder of the applicants are the children of Hakkı Kaya, who has been missing since 16 November 1996.
9.  On 16 November 1996 at about 3 p.m. Hakkı Kaya and his two friends Mr Ahmet Yaşar and a certain Mehmet (full name unknown) were walking in the city centre in Diyarbakır. While they were in front of the Forest Directorate building, a white Renault estate car, with the registration number 06 EKN 22, approached them. Three men dressed in civilian clothes and carrying walkie-talkies introduced themselves as police officers and carried out an identity check. They then forced Mr Kaya into the vehicle, stating that he had to go to the police station to make a statement.
10.  On 28 November 1996 the second applicant filed a complaint with the Diyarbakır State Security Court Public Prosecutor’s office and requested the Prosecutor to investigate Hakkı Kaya’s disappearance. On the same day, Hakkı Kaya’s brother, Mr Şefik Kaya, petitioned the Diyarbakır Public Prosecutor’s office and requested information about his brother’s whereabouts.
11.  On 4 December 1996 the police took a statement from Mr Ahmet Yaşar, an eye-witness to Hakkı Kaya’s abduction. In his statement, Mr Yaşar explained that on the day of the incident, while he and his two friends were walking in front of the Diyarbakır Forest Directorate Building, a white Toros estate car with the registration number 06 EKN 22 had approached them. The men in the car carried out an identity check and told Mr Yaşar that he could leave. Mr Yaşar explained that, as everything had happened very quickly, he was unable to give a precise description of these men. He recalled however that one of them was blond, and another had curly hair. He had no idea for whom they were working.
12.  On 5 January 1997 the Diyarbakır Gendarmerie Commander informed the Diyarbakır State Security Court Public Prosecutor that Hakkı Kaya had not been taken into custody.
13.  On 17 March 1997 the Diyarbakır State Security Court Public Prosecutor declared a lack of jurisdiction and transferred the case to the Diyarbakır Chief Public Prosecutor’s office. The latter commenced an investigation into Mr Kaya’s disappearance and requested the Diyarbakır Security Directorate to search for him. Since that date, the Security Directorate has been sending regular reports to the Prosecutor and checking the customs’ records to see whether Hakkı Kaya has left the country.
14.  On 27 March 1997 the Human Rights Investigation Committee at the Turkish Grand National Assembly informed the applicants that Hakkı Kaya was not in detention. The Committee further informed the applicants that the car with the registration number 06 EKN 22 was a Fiat Şahin, and not a white Toros estate car as alleged, and it belonged to a certain Y.C., who resided in Ankara.
15.  On 7 September 1998 the police took Efendi Kaya’s statement. In his statement, Efendi Kaya explained that his father had been missing since November 1996 and that he had not received any news from him since.
16.  On 28 January 2000 the applicants filed a further complaint with the Public Prosecutor. On 12 June 2000 the police once again took a statement from Efendi Kaya, who repeated his statement of 7 September 1998.
17.  On 13 June 2000 the police took a statement from Mr Recep Girçek, a neighbour of the Kaya family. In his statement, Mr Girçek explained that Hakkı Kaya had been missing since November 1996; however he had no information about his disappearance or his whereabouts.
18.  On 22 March 2001 the authorities took another statement from Efendi Kaya, who repeated his previous statements.
19.  On 11 March 2004 an interview with Mr Abdulkadir Aygan, a former member of the PKK and allegedly a member of JITEM (the Gendarme Intelligence Service), was published in the Ülkede Özgür Gündem newspaper. In this interview, Mr Aygan stated that Hakkı Kaya was one of the persons who had been killed by JITEM. He explained that Mr Kaya’s body had been buried at the Diyarbakır–Silvan motorway, between the villages of Karacali and Han. The applicants submitted a copy of this newspaper article to the Public Prosecutor for further investigation.
20.  On 6 April 2004 the Diyarbakır Security Department informed the Diyarbakır Public Prosecutor that Abdülkadir Aygan had been sentenced to 15 years’ imprisonment for being a member of a terrorist organisation in 1986. However, as he had benefited from the repentance law of 1985, he had been released from prison and his whereabouts were unknown. The Public Prosecutor continued searching for Abdülkadir Aygan but was not able to locate him.
21.  On 8 June 2004 the second applicant filed a complaint against Abdülkadir Aygan for killing Hakkı Kaya.
22.  The parties submitted various documents with a view to substantiating their claims. These documents, in so far as they are relevant, may be listed as follows.